Imaging apparatus and recording medium

ABSTRACT

In a digital camera  1 , when the shutter button is half-depressed (Y at S 2 ), face detection processing is performed on periodically imaged frame images until it is fully depressed (N at S 6 ), and face detection results are cyclically stored in a detection result storage area. When it is fully depressed (Y at S 6 ), a still-image imaging operation is performed, and the face detection processing is performed on an imaged still-image (S 7  and S 8 ). Then, after a high priority face detection result is selected from among the face detection results currently stored in the detection result storing area (S 9 ), the selected face detection result and the face detection result of the still-image are compared and judged whether or not they are in agreement (S 10  and S 11 ). When judged not to be in agreement, the still-image is displayed as a preview and the warning display of this disagreement is performed (S 13 ).

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2008-050221, filed Feb. 29,2008, the entire contents of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging apparatus providing afunction for detecting a photographic subject, and a recording medium inwhich a program thereof is recorded.

2. Description of the Related Art

A face detection technology is known in which a face within image datais detected (refer to Japanese Patent Application Laid-Open (Kokai)Publication No. 2006-293720).

When a camera implementing the above-described face detection technologyis used, a detected face can be focused, and an image can be obtained inwhich the face is in focus. However, even if a face detected in aLive-view display state is in a state desired by a photographer, a statenot desired by the photographer is sometimes recorded by the time arecording instruction is given.

SUMMARY OF THE INVENTION

The present invention has been conceived in light of the above-describedconventional issues, and is to provide an imaging apparatus and aprogram thereof that allows the user to easily recognize whether or nota sudden change has occurred to a photographic subject between acondition before imaging and a condition when a still-image is actuallyimaged.

In accordance with one aspect of the present invention, there isprovided an imaging apparatus comprising: a first imaging control meansfor periodically imaging; a first detection means for detecting apredetermined photographic subject from an image data imaged by thefirst imaging control means; an instruction means for instructing toimaging still-image during periodic imaging by the first imaging controlmeans; a second imaging control means for imaging still-image wheninstructed by the instruction means; a second detection means fordetecting a predetermined photographic subject from a still-image dataimaged by the second imaging control means; a comparison means forcomparing a result of the photographic subject detection by the firstdetection means with a result of the photographic subject detection bythe second detection means; and an informing means for informing acomparison result by the comparison means.

In accordance with another aspect of the present invention, there isprovided a computer-readable storage medium having a program storedthereon that is executable by a computer included in an imagingapparatus to cause the computer to perform a process comprising: a firstimaging control processing for periodically imaging; a first detectionprocessing for detecting a predetermined photographic subject from animage data imaged by the first imaging control processing; aninstruction processing for instructing to imaging still-image duringperiodic imaging by the first imaging control processing; a secondimaging control processing for imaging still-image when instructed bythe instruction processing; a second detection processing for detectinga predetermined photographic subject from a still-image data imaged bythe second imaging control processing; a comparison processing forcomparing a result of the photographic subject detection by the firstdetection processing with a result of the photographic subject detectionby the second detection processing; and an informing processing forinforming a comparison result by the comparison processing.

The above and further objects and novel features of the presentinvention will more fully appear from the following detailed descriptionwhen the same is read in conjunction with the accompanying drawings. Itis to be expressly understood, however, that the drawings are for thepurpose of illustration only and are not intended as a definition of thelimits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a digital camera according to an embodimentof the present invention;

FIG. 2 is a flowchart showing an operation of a digital camera 1according to the embodiment;

FIG. 3A is an example diagram of a displayed Live-view and facedetection frames;

FIG. 3B is an example diagram of still-image data displayed as apreview, and an identification display of a face area;

FIG. 4A is an example diagram of an area subjected to face detection ina variation example; and

FIG. 4B is a diagram of still-image data displayed as a preview and awarning display in the variation example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will hereinafter be described in detail withreference to the preferred embodiments shown in the accompanyingdrawings.

Embodiment

FIG. 1 is a block diagram showing an electrical schematic of a digitalcamera 1 actualizing an image apparatus of the present invention. Thedigital camera 1 includes an imaging lens 2, a lens driving block 3, anaperture 4, a charge-coupled device (CCD) 5, a driver 6, a timinggenerator (TG) 7, a unit circuit 8, an image generating section 9, acentral processing unit (CPU) 10, a key input section 11, a memory 12, adynamic random access memory (DRAM) 13, a flash memory 14, an imagedisplay section 15, and a bus 16.

The imaging lens 2 is formed by a plurality of lens groups not shown andincludes at least a focus lens 2A. The lens driving block 3 is connectedto the focus lens 2A. The lens driving block 3 includes a focus motorand a focus motor driver. The focus motor drives the focus lens 2A inthe optical axis direction. The focus motor driver drives the focusmotor in adherence to a control signal sent from the CPU 10 not shown.

The aperture 4 includes a driver circuit (not shown), and the drivercircuit activates the aperture 4 in adherence to a control signal sentfrom the CPU 10.

The aperture 4 refers to a mechanism for controlling an amount of lightirradiated from the imaging lens 2.

The driver 6 drives the CCD 5 (image sensor element). The CCD 5photo-electrically converts the light intensity of the respective colorsin a red-green-blue (RGB) value of a photographic subject image to animaging signal at a constant cycle and outputs the imaging signal to theunit circuit 8. The operation timing of this driver 6 and the unitcircuit 8 is controlled by the CPU 10 via the TG 7. Note that the CCD 5has the color filters of Bayer array, and also has a function of anelectronic shutter. The shutter speed of this electronic shutter iscontrolled by the CPU 10 via the driver 6 and the TG 7.

The TG 7 is connected to the unit circuit 8. The unit circuit 8 includesa correlated double sampling (CDS) circuit, an automatic gain control(AGC) circuit, and an analog-to-digital (A/D) converter. The CDS circuitperforms correlated double sampling on an imaging signal outputted fromthe CCD 5 and holds the sampled imaging signal. The AGC circuit performsautomatic gain control on the sampled imaging signal. The A/D converterconverts the automatic-gain-controlled analog imaging signal to adigital signal. The imaging signal outputted from the CCD 5 is sent tothe image generating section 9 as a digital signal via the unit circuit8.

The image generating section 9 performs processing, such as γ correctionprocessing and white balance processing on image data sent from the unitcircuit 8, and generates luminosity color-difference signals (YUV data).The generated luminosity color-difference signal image data is stored inthe DRAM 13 (buffer memory). In short, the image generating section 9performs imaging processing on image data outputted from the CCD 5.

The CPU 10 is a one-chip microcomputer having a function that performsimaging control on the CCD 5, record processing for compressing imagedata stored in the buffer memory and recording the compressed image datain the flash memory 14, and display processing for displaying image datastored in the buffer memory, and controls each section of the digitalcamera 1. In addition, the CPU 10 includes a clock circuit.

Particularly, the CPU 10 includes an imaging control section 101, astill-image imaging control section 102, a face detection section 103,and a comparative judgment section 104. The imaging control section 101periodically controls imaging of image data of a photographic subject.The still-image imaging control section 102 controls still-image imagingof a photographic subject. The face detection section 103 detects a facein periodically imaged image data and still-image data obtained througha still-image imaging operation. The comparative judgment section 104compares a face detection result of face detection processing performedon image data imaged by the imaging control section 101 and a facedetection result of a face detection processing performed on image dataimaged by the still-image imaging control section 102, and judgeswhether or not the face detection results are in agreement.

According to the embodiment and in a variation example describedhereafter, the CPU actualizes an imaging control means, a firstphotographic subject detection means, an imaging instruction means, astill-image imaging control means, a second photographic subjectdetection means, a comparison means, a informing means, a judgmentmeans, a display means, an imaging-preparation instruction means, and asmile detection means.

The key input section 11 includes a plurality of operation keys such asa shutter button enabling both half-depression and full depression, amode selection key, a cross key, a SET key, and a cancel key, andoutputs operation signals that correspond to the key operationsperformed by the user to the CPU 10.

The memory 12 stores a control program required for the CPU 10 tocontrol each section of the digital camera 1 and necessary data, and theCPU 10 operates in accordance with this program.

The DRAM 13 is used as a buffer memory for temporarily storing imagedata imaged by the CCD 5 sent from the CPU 10, and also used as aworking memory of the CPU 10. The DRAM 13 also temporarily stores a facedetection result sent from the face detection section 103.

The flash memory 14 is a storage medium storing therein compressed imagedata.

The image display section 15 (display means) includes a color liquidcrystal display (LCD) and a driver circuit thereof. In an imagingstand-by state, the image display section 15 displays a photographicsubject imaged by the CCD 5 as a Live-view. In the playback of recordedimage, the image display section 15 reads out recorded image from theflash memory 14 and displays an expanded version of the recorded image.

B. Operations of the Digital Camera 1

An operation of the digital camera 1 according to the embodiment willhereinafter be described with reference to a flowchart in FIG. 2.

When the imaging mode is set by the user operation of the mode selectionkey, the imaging control section 101 of the CPU 10 initiates processingfor imaging a photographic subject using the CCD5 at a predeterminedframe rate, and initiates a so-called Live-view display (Step S1). Inthe Live-view display, the imaging control section 101 stores in thebuffer memory (DRAM 13) frame image data (YUV data) of luminosity colordifference signals sequentially imaged by the CCD 5 and generated by theimage generating section 9, and the image display section 15 displaysimages based on the stored frame image data.

Next, at Step S2, the CPU 10 judges whether or not the user hashalf-depressed the shutter button. This judgment is made based onwhether or not an operation signal corresponding to the half-depressionoperation of the shutter button is sent from the key input section 11.

At this time, ordinarily, the user half-depresses the shutter buttonwhen the photographic subject is almost in a desired state.

When judged that the shutter button has not been half-depressed, the CPU10 remains at Step S2 until the shutter button is half-depressed. Whenjudged that the shutter button has been half-depressed, the CPU 10proceeds to Step S3. The face detection section 103 of the CPU 10performs face detection processing for detecting a face on frame imagedata most recently imaged by the CCD 5. At this time, the face detectionsection 103 detects whether or not a human face is present within theentire area (entire range of field angle) of the imaged frame imagedata. In other words, a range subjected to the face detection processingis the entire area of the image data.

The face detection processing is a known art and thus will not bedescribed in detail. However, for example, a method can be used in whichfeature data (feature data of eyes, eyebrows, nose, mouth, ears, and thelike) of a typical human face is stored in advance is compared withimage data imaged, and a degree of coincidence between the feature dataand the image data is determined. An area in which the degree ofcoincidence is a predetermined value or more is detected as a humanface. Alternatively, a method can be used in which a skin-color area isdetected, and when a contour of the detected skin-color area is acontour of a typical human face stored in advance, the area is detectedas a face.

Next, at Step S4, the face detection section 103 of the CPU 10 performsprocessing for cyclically storing a face detection result in thedetection result storage area of the buffer memory. This face detectionresult refers to the number of faces detected, and the positions and thesizes of the detected faces. In cyclical storage, the face detectionresults of frame image data are sequentially stored until the detectionresult storage area of the buffer memory is full. When the detectionresult storage area is full, the oldest face detection result among aplurality of face detection results stored in the detection resultstorage area is overwritten by the face detection result of the facedetection processing performed on new frame image data, and the new facedetection result is stored. As a result, face detection results for mostrecently imaged frame image data to frame image data imaged apredetermined amount of time earlier (a predetermined number of imagesearlier) are stored.

Next, the CPU 10 initiates processing for displaying a face detectionframe superimposed on the Live-view, based on the most recent facedetection result (Step S5).

Here, the displaying of a face detection frame based on a face detectionresult refers to the displaying of a frame called face detection framein a face area corresponding to the detected position and size of eachface.

FIG. 3A is an example diagram of the displayed Live-view and the facedetection frame.

In FIG. 3A, a photographic subject (person) 21, a photographic subject(person) 22, and a photographic subject (person) 23 have been imaged anddisplayed as the Live-view. Also, face detection frames 31 superimposedon the Live-view have been displayed in the detected face areas. Inother words, the respective faces of the photographic subject 21, thephotographic subject 22, and the photographic subject 23 have beendetected, and the face detection frames 31 have been displayed on eachface.

This display enables the user to check whether or not the photographicsubjects are in a state that the user wishes to image, and when thephotographic subjects are not in the intended state, enables the user tocorrect the state of the photographic subjects to the intended state bygiving an instruction to the photographic subject and the like.

Next, the CPU 10 judges whether or not the user has fully depressed theshutter button. This judgment is made based on whether or not anoperation signal corresponding to the full-depression operation of theshutter button has been sent from the key input section 11 (Step S6).

At this time, when the photographic subjects are in the intended state,the user fully depresses the shutter button.

When judged at Step S6 that the shutter button has not been fullydepressed the CPU 10 returns to Step S3 until the shutter button isfully depressed. As a result, the face detection processing is performedon each of frame image data sequentially imaged by the CCD 5, and theface detection result of the face detection processing is cyclicallystored in the detection result storage area of the buffer memory. Notethat the operations at Step S3 to Step S5 are completed before the nextframe image data is imaged.

On the other hand, when judged at Step S6 that the shutter button hasbeen fully depressed, the still-image imaging control section 102 of theCPU 10 performs the still-image imaging processing (Step S7).

Next, the face detection section 103 of the CPU 10 performs the facedetection processing for detecting a face on the still-image data imagedby the still-image imaging processing (Step S8). At this time, the facedetection section 103 detects whether or not a human face is present inthe entire area (entire range of the field angle) of the imaged frameimage data.

Next, the comparative judgment section 104 of the CPU 10 selects a highpriority face detection result from among the face detection resultsobtained before the full depression of the shutter button (Step S9). Thepriority of face detection results is determined based on all thevarious factors such as the number of detected faces, the proximity ofeach detected face to the center of the field angle, and the size ofeach detected face. Therefore, the priority of the face detection resultis higher when more faces are detected by the face detection processingperformed on the frame image data, when each face detected by the facedetection processing performed on the frame image data is closer to thecenter of the field angle, or when each face detected by the facedetection processing performed on the frame image data is larger. As aresult, the highest priority face detection result is selected fromamong the face detection results stored in the detection result storagearea of the buffer memory or, in other words, from among the facedetection results of each of frame image data stored immediately beforethe full-depression of the shutter button to a predetermined amount oftime earlier (a predetermined number of images earlier).

Here, a face detection result such as that shown in FIG. 3A is selected.

Next, the comparative judgment section 104 of the CPU 10 compares theselected face detection result and the face detection result from theface detection processing at Step S8 (Step S10), and judges whether ornot the face detection results are in agreement (Step S11).

This comparison and the judgment regarding the agreement are performedas follows. First, the number of faces, the position of each face, andthe size of each face of the selected face detection result and thenumber of faces, the position of each face, and the size of each face ofthe face detection result from the face detection processing at Step S8are compared, and then whether or not they are in agreement is judged.

Specifically, whether or not the number of faces in the selected facedetection result and the number of faces in the face detection resultfrom the face detection processing at Step S8 are in agreement, whetheror not the position of each face in the selected face detection resultand the position of each corresponding face in the face detection resultfrom the face detection processing at Step S8 are in agreement within apredetermined range, and whether or not the size of each face in theselected face detection result and the size of each corresponding facein the face detection result from the face detection processing at StepS8 are in agreement within a predetermined size are compared. When allof these requirements are satisfied, the face detection results arejudged to be in agreement.

When judged at Step S11 that the selected face detection result and theface detection result from the face detection processing at Step S8 arein agreement, the image display section 15 displays the still-image dataimaged at Step S7 as a preview (Step S12) and the CPU 10 proceeds toStep S15.

On the other hand, when judged at Step S11 that the selected facedetection result and the face detection result from the face detectionprocessing at Step S8 are not in agreement, the image display section 15displays the still-image data imaged at Step S7 as a preview anddisplays a warning stating that the face detection results are not inagreement (Step S13). This warning is displayed by the identificationdisplay of a face area that is based on the position and the size of aface judged not to be in agreement which is in the face detection resultselected at Step S9.

FIG. 3B is an example diagram of still-image data displayed as a previewand the identification display of a face area.

In FIG. 3B, the eyes of the photographic subject 22 are closed in thestill-image data. Therefore, the face of the photographic subject 22will not be detected by the face detection processing. As a result, aface area that corresponds to the face area of the photographic subject22, among the face detection frames 31 (detected face areas) in FIG. 3Aindicating the selected face detection result, is not found in FIG. 3B.Therefore, by superimposing a warning frame 32 on the still-image dataand displaying the warning frame 32 in the same area as the facedetection frame 31 of the photographic subject 22 shown in FIG. 3A, itis possible to warn (inform) the user of an area in which a suddenchange has occurred between before and after the full-depression of theshutter button.

Next, when the still-image data is displayed as a preview and thewarning is displayed, the CPU 10 judges whether or not the user hasperformed an operation to give a recording instruction (Step S14).

At this time, in the case where the user has operated the SET key, theCPU 10 judges that the user has performed the operation to generate arecording instruction, and in the case where the user has operated thecancel key, the CPU 10 judges that the user has given an instruction notto record.

When judged at Step S14 that a recording instruction operation isperformed, the CPU 10 proceeds to Step S15. When judged that a recordinginstruction operation is not performed or, in other words, aninstruction not to record is given, the CPU 10 returns to Step S1.

At Step S15, the CPU 10 compresses the imaged still-image data andrecords the compressed still-image data to the flash memory 14. The CPU10 then returns to Step S1.

Note that when another mode is selected during the imaging mode by theoperation of the mode selection key, the imaging mode is terminated.

As described above, according to the embodiment, the face detectionresult of the face detection processing performed on a Live-view and theface detection result of the face detection processing performed on thestill-image data are compared, and whether or not the face detectionresults are in agreement within a predetermined range is judged. Then,when the face detection results are not in agreement, the still-imagedata is displayed as a preview, and a warning stating that the facedetection results are not in agreement is displayed. Therefore, it iseasily recognized by the user whether or not a sudden change hasoccurred to the photographic subject between the Live-view beforeimaging and the imaged still-image data.

In addition, the warning is displayed by the warning frame 32 beingdisplayed in the face area of a face that is not in agreement, amongfaces detected in the Live-view. Therefore, an area that is not inagreement is easily recognized by the user.

Furthermore, when the warning is displayed, still-image data is notrecorded unless a recording instruction is given by the user. Therefore,the recording capacity the flash memory 14 is not wasted.

VARIATION EXAMPLES

The following variation examples are also possible according to theembodiment.

(01) According to the above-described embodiment, the highest priorityface detection result is selected from among face detection results foreach of frame image data imaged immediately before the full-depressionof the shutter button to a predetermined amount of time earlier (apredetermined number of images earlier). However, the face detectionresult of the face detection processing performed on frame image dataimaged immediately before the full-depression of the shutter button maybe selected regardless of priority. Alternatively, the face detectionresult of the face detection processing performed on frame image dataimaged immediately after the half-depression of the shutter button maybe selected regardless of priority.

In these cases, the face detection results are not required to becyclically stored. In addition, when the face detection result of theface detection processing performed on frame image data imagedimmediately after the half-depression of the shutter button is selected,the face detection processing is required to be performed only onceafter the half-depression of the shutter button.

Alternatively, a face detection result obtained a predetermined amountof time earlier (a predetermined number of images earlier) than thefull-depression of the shutter button may be selected from among facedetection results for each of frame image data stored immediately beforethe full-depression of the shutter button to a predetermined amount oftime earlier (a predetermined number of images earlier).

As a result, in the case where the state of the photographic subjectchanges between the judgment by the user that the photographic subjectis in the desired state and the full-depression of the shutter button,and the face detection result of the face detection processing performedon the frame image data imaged immediately before the full-depression ofthe shutter button is a face detection result of frame image datadiffering from that intended by the user, or in the case where the userjudges that the state of the photographic subject is desirable even whenit is of low priority, a situation can be prevented in which a resultwith high priority is selected and comparison is performed using frameimage data differing from that intended by the user.

(02) According to the above-described embodiment, the priority of facedetection results is determined based on all the various factors such asthe number of detected faces, the proximity of each detected face to thecenter of the field angle, and the size of each detected face. However,the priority may be determined based on at least one factor among thenumber of detected faces, the proximity of each detected face to thecenter of the field angle, and the size of each detected face.Alternatively, the priority may be determined based on other factors.

The other factors are, for example, whether or not a face registered inadvance is detected, the number of detected faces that are registered inadvance, a smile evaluation value obtained through smile detection, anda degree of coincidence regarding whether or not a detected photographicsubject is the same photographic subject.

As a result, it is easily recognized by the user whether or not a suddenchange has occurred to the photographic subject between the Live-viewbefore imaging and the imaged still-image data.

(03) According to the above-described embodiment, the number of detectedfaces, the positions of detected faces, and the sizes of detected facesare compared to judge whether or not the face detection results are inagreement. However, whether or not face detection results are inagreement may be judged through the comparison of only the number offaces, the comparison of only the positions of faces, or the comparisonof only the size of faces.

Also, whether or not the face detection results are in agreement may bejudged based on more than one condition among the number of detectedfaces, the positions of detected faces, and the sizes of detected faces.

As a result, it is easily recognized by the user whether or not a suddenchange has occurred to the photographic subject between the Live-viewbefore imaging and the imaged still-image data.

(04) According to the above-described embodiment, the number of faces,the position of each face, and the size of each face detected by theface detection processing performed on a Live-view, and the number offaces, the position of each face, and the size of each face detected bythe face detection processing performed on the still-image data arerespectively compared, and whether or not they are in agreement isjudged. However, the position and the size of only the face closest tothe center of the field angle among a plurality of detected faces may becompared and judged whether or not they are in agreement. Alternatively,the position and the size of only the largest face among a plurality ofdetected faces may be compared and judged whether or not they are inagreement. This is because, the face closest to the center of the fieldangle or the largest face is considered to be a main photographicsubject that the user wishes to image and, therefore, the state of themain photographic subject is the most important.

(05) According to the above-described embodiment, the face detectionprocessing on still-image data is performed on the entire area ofstill-image data (Step S8 in FIG. 2). However, when the shutter buttonis fully depressed, the face detection processing may be performed ononly each area that is based on the position and the size of a facewhich is a face detection result selected at Step S9 in still-imagedata. In this case, the operation at Step S9 is required to be performedbefore the operation at Step S8. Here, the above described each areathat is based on the position and the size of a face may be the samearea as a detected face area or an area larger than a detected facearea.

FIG. 4A is an example diagram of an area subjected to face detectionwhen a face detection result such as that shown in FIG. 3A is selected.Here, areas 33, which are the areas based on the position and the sizeof each face and are face detection results such as that shown in FIG.3A, are areas larger than a detected face area.

As a result of the face detection processing being performed on eacharea 33 shown in FIG. 4A in the still-image data, the load of the facedetection processing is reduced. Moreover, when a face is detected ineach area 33, the selected face detection result and the face detectionresult of the face detection processing performed on the still-imagedata are judged to be in agreement, and thus the comparative judgmentprocessing is light.

(06) According to the above-described embodiment, the warning isdisplayed by still-image data being displayed as a preview and thewarning frame 33 being superimposed on the same area as a face area thatis based on the position and the size of a face judged not to be inagreement in the face detection result selected at Step S9. However,identification display may be performed by the enlarged display of theimage data of the same area as a face area that is based on the positionand the size of a face judged not to be in agreement in still-image datadisplayed as a preview.

FIG. 4B is an example diagram of still-image data displayed as a previewat this time and the warning display.

As is clear from FIG. 4B, the image data within the warning frame 32shown in FIG. 3B is displayed in an enlarged state. As a result, an areathat is not in agreement is easily recognized by the user.

(07) According to the above-described embodiment, when a selected facedetection result and the face detection result of the face detectionprocessing performed on still-image data are not in agreement,information that the face detections results are not in agreement isproactively informed by the warning being displayed. Also, when the facedetection results are in agreement, information that the face detectionresults are in agreement is passively informed by the warning not beingdisplayed. However, the information that face detection results are inagreement may be displayed when face detection results are in agreement,and the information that face detection results are not in agreement maybe displayed when face detection results are not in agreement. As aresult, it is easily recognized by the user whether or not a suddenchange has occurred to the photographic subject between the Live-viewbefore imaging and the imaged still-image data.

The information that face detection results are in agreement and theinformation that face detection results are not in agreement may be atext. Alternatively, a symbol or the like indicating whether or not theface detection results are not in agreement may be displayed.Furthermore, a frame, referred to as an agreement frame, may bedisplayed over a face that is in agreement. This enables the user toknow that face detection results are in agreement when this agreementframe is displayed on all faces in still-image data, and to know thatface detection results are not in agreement when the agreement frame isonly displayed on some faces in still-image data.

On the other hand, the information that face detection results are notin agreement may not be displayed (no warning is displayed) when facedetection results are not in agreement, and the information that facedetection results are in agreement may be displayed when face detectionresults are in agreement.

The information that face detection results are in agreement may be atext stating that face detection results are in agreement.Alternatively, a symbol or the like indicating that face detectionresults are in agreement may be displayed.

Moreover, the warning may be made by sound, vibrations, and the like,rather than being displayed. When face detection results are not inagreement, the information that the face detection results are not inagreement may be informed by the Live-view being displayed instead ofthe preview.

In short, any method can be used as long as whether or not facedetection results are in agreement is clear. As a result, it is easilyrecognized by the user whether or not a sudden change has occurred tothe photographic subject between the Live-view before imaging and theimaged still-image data.

(08) According to the above-described embodiment, when face detectionresults are judged not to be in agreement at Step S11, the still-imagedata is displayed as a preview and the warning is displayed, and whenthe user gives a recording instruction, the still-image data isrecorded. However, when face detection results are judged not to be inagreement at Step S11, the operation may return to Step S1 after thestill-image is displayed as a preview and the warning is displayed. Inother words, still-image data is not recorded when the warning isdisplayed.

Alternatively, when face detection results are judged not to be inagreement at Step S11, after the still-image data is displayed as apreview and the warning is displayed, the operation may proceed to StepS15 at which the still-image data is recorded.

As a result, it is easily recognized by the user whether or not a suddenchange has occurred to the photographic subject between the Live-viewbefore imaging and the imaged still-image data.

(09) According to the above-described embodiment, when face detectionresults are judged not to be in agreement at Step S11, the still-imagedata is displayed as a preview and the warning is displayed. However,this warning may be made by displaying the still-image data as a previewwhen the face detection results are judged to be in agreement at StepS11, and not displaying the still-image data as a preview when the facedetection results are judged not to be in agreement at Step S11. In thiscase (when face detection results are judged not to be in agreement atStep S11), the operation may return to Step S1, or proceed to Step S14or Step S15. As a result, it is easily recognized by the user whether ornot a sudden change has occurred to the photographic subject between theLive-view before imaging and the imaged still-image data.

(10) According to the above-described embodiment, imaged still-imagedata is displayed as a preview (Step S12 and Step S13) regardless ofwhether or not the face detection results are in agreement at Step S11.However, the still-image data may not be displayed as a preview.

In this case, when the face detection results are judged to be inagreement at Step S11, the operation may proceed directly to Step S15.Also, when the face detection results are judged not to be in agreementat Step S11, only the warning may be displayed at Step S13, and theoperation may proceeds to Step S14. At this time, the warning displayindicates that the face detection results are not in agreement usingtext, a symbol, and the like.

(11) According to the above-described embodiment, the warning isdisplayed through an identification display of a face area that is basedon the position and the size of a face judged not to be in agreement inthe face detection result selected at Step S9 (Step S13). However,information that the face detection results are in agreement may besimply displayed by a text, a symbol, and the like.

(12) According to the above-described embodiment, only faces aredetected. However, a smile detection process may be provided, and awarning may be displayed when a smile evaluation value indicating adegree of smile detected by the smile detection processing performed ona Live-view and a smile evaluation value detected by the smile detectionprocessing performed on still-image data are not in agreement within apredetermined range.

As the above-described embodiment, this smile evaluation value detectedby the smile detection processing performed on the Live-view may be asmile evaluation value detected by the smile detection processingperformed on frame image data imaged immediately before thefull-depression of the shutter button. Alternatively, the smileevaluation value may be that detected by the smile detection processingperformed on frame image data imaged immediately after thehalf-depression of the shutter button. Also, the smile evaluation valuemay be the highest or the lowest smile evaluation value or a mean smileevaluation value among smile evaluation values detected by the smiledetection processing performed on each of frame image data imagedimmediately before the full-depression of the shutter button to apredetermined amount of time earlier (a predetermined number of imagesearlier). Furthermore, the smile evaluation value may be that detectedby the smile detection process performed on a piece of frame image dataimaged a predetermined amount of time earlier (a predetermined number ofimages earlier) than the full-depression of the shutter button.

(13) According to the above-described embodiment, only faces aredetected. However, an individual identification process may beperformed, and when a registered face is present, a comparison may beperformed on only the result of individual identification of theregistered face, and the judgment whether or not they are not agreementmay be made. In other words, the result of individual identification(the number of faces, and the position and the size of the faces) duringa Live-view and the result of individual identification (the number offaces, and the position and the size of the faces) of still-image dataare compared and judged whether or not they are in agreement.

(14) According to the above-described embodiment, human faces aredetected. Then, the face detection result of a Live-view and the facedetection result of still-image data are compared and judged whether ornot they are in agreement. However, the detection is not limited tofaces. Smile detection, individual identification for identifying acertain person, the detection of facial feature data (feature data foreyes, eyebrows, nose, mouth, ears, and the like), face detection foranimals, animal detection for detecting animals, and the like may beperformed. In short, it is only required is that a predeterminedphotographic subject be detected.

(15) According to the above-described embodiment, detection results,which are the number of faces, and the position and the size of theface, are compared and judged whether or not they are in agreement.However, the degree of coincidence with facial feature data (featuredata for eyes, eyebrows, nose, mouth, ears, and the like) may also becompared and judged whether or not they are in agreement.

For example, in cases where a face is detected even when the eyes of thephotographic subject is closed, or the photographic subject has lookedaway, the warning is not displayed even when the eyes of thephotographic subject 22 are closed as shown in FIG. 3B. However, it goeswithout saying that a state in which the eyes of the photographicsubject are closed, a state in which the photographic subject has lookedaway, and the like are photographic subject states not intended by theuser. Therefore, even when a face is detected, the degree of coincidenceis taken into consideration, and when the degree of coincidence is notwithin a predetermined range, the judgment that face detection resultsare in agreement is not made at Step S11.

Note that a judgment whether or not they are in agreement may be made bycomparison of only the degree of coincidence with facial feature data.In other words, only an eye area or a mouth area may be compared.

(16) Furthermore, the above-described embodiment and the above-describedmodifications (01) to (15) may be randomly combined as the modification.

(17) The individual embodiments of the present invention as describedabove are merely examples as a best mode for carrying out the invention,and aims to facilitate understanding of the principle and the structureof the present invention. It is not intended to limit the scope of thepresent invention.

Therefore, it should be construed that various variations andmodifications for the above-described embodiment of the presentinvention be included within the scope of the present invention and beprotected by the scope of the present invention.

Lastly, in the individual embodiments as described above, a case wherean imaging apparatus of the present invention is applied to the digitalcamera 1 is described. However, the present invention is not limited tothe above-described embodiments. In other words, the present inventionmay be applied to any apparatus as long as it can photograph aphotographic subject and detect a predetermined photographic subject.

While the present invention has been described with reference to thepreferred embodiments, it is intended that the invention be not limitedby any of the details of the description therein but includes all theembodiments which fall within the scope of the appended claims.

1. An imaging apparatus comprising: first imaging control means forperforming periodic imaging; first detection means for detecting apredetermined photographic subject from image data imaged by the firstimaging control means; instruction means for instructing imaging astill-image during the periodic imaging by the first imaging controlmeans; second imaging control means for imaging a still-image wheninstructed by the instruction means; second detection means fordetecting a predetermined photographic subject from still-image dataimaged by the second imaging control means; comparison means forcomparing a result of the photographic subject detection by the firstdetection means with a result of the photographic subject detection bythe second detection means; and informing means for informing of acomparison result by the comparison means.
 2. The imaging apparatusaccording to claim 1, wherein the informing means accordingly informs byan indication when the comparison result by the comparison meansindicates that the result of the photographic subject detection by thefirst detection means is not in agreement with the result of thephotographic subject detection by the second detection means.
 3. Theimaging apparatus according to claim 1, further comprising: a display;wherein the informing means accordingly informs by controlling thedisplay to display the still-image data imaged by the second imagingcontrol means when the comparison result by the comparison meansindicates that the result of the photographic subject detection by thefirst detection means is in agreement with the result of thephotographic subject detection by the second detection means, andaccordingly informs by restarting imaging by the first imaging controlmeans without controlling the display to display the still-image dataimaged by the second imaging control means when the comparison result bythe comparison means indicates that the result of the photographicsubject detection by the first detection means is not in agreement withthe result of the photographic subject detection by the second detectionmeans.
 4. The imaging apparatus according to claim 1, furthercomprising: a display; wherein the informing means accordingly informsby controlling the display to display an indication when the comparisonresult by the comparison means indicates that the result of thephotographic subject detection by the first detection means is not inagreement with the result of the photographic subject detection by thesecond detection means.
 5. The imaging apparatus according to claim 4,further comprising: display control means for controlling the display todisplay the image data imaged by the first imaging control means and thestill-image data imaged by the second imaging control means; wherein theinforming means informs by controlling the display to performidentification display of a photographic subject area detected by thefirst detection means or the second detection means which is not inagreement in the still-image data displayed on the display by thedisplay control means when the comparison results by the comparisonmeans indicates that the result of the photographic subject detection bythe first detection means is not in agreement with the result of thephotographic subject detection by the second detection means.
 6. Theimaging apparatus according to claim 4, wherein the informing meanscontrols the display to perform identification display by enlargingimage data of a photographic subject area detected by the firstdetection means or the second detection means which is not in agreementin the still-image data displayed on the display by the display controlmeans when the comparison result by the comparison means indicates thatthe result of the photographic subject detection by the first detectionmeans is not in agreement with the result of the photographic subjectdetection by the second detection means.
 7. The imaging apparatusaccording to claim 1, wherein the comparison means performs thecomparison by determining at least one of whether or not numbers ofdetected photographic subjects are in agreement within a predeterminedrange, whether or not positions of detected photographic subjects are inagreement within a predetermined range, and whether or not sizes ofdetected photographic subjects are in agreement within a predeterminedrange, when comparing the result of the photographic subject detectionperformed by the first detection means and the result of thephotographic subject detection performed by the second detection means.8. The imaging apparatus according to claim 1, wherein each of the firstdetection means and the second detection means comprises smile detectionmeans for detecting a smile evaluation value indicating a degree ofsmile of a photographic subject, and wherein the comparison meanscompares smile evaluation values detected by the first detection meansand the second detection means.
 9. The imaging apparatus according toclaim 1, wherein the comparison means compares whether or not a resultof the photographic subject detection performed by the first detectionmeans and a result of the photographic subject detection performed bythe second detection means are in agreement.
 10. The imaging apparatusaccording to claim 1, further comprising: further instruction means forinstructing to prepare for imaging a still-image during the periodicimaging by the first imaging control means; wherein the comparison meanscompares a result of the detection by the first detection means from theimage data imaged by the first imaging control means with a result ofthe detection by the second detection means when preparation for imagingis instructed by the further instruction means.
 11. The imagingapparatus according to claim 1, wherein the first detection meansdetects a predetermined photographic subject from the image data imagedby the first imaging control means immediately before imaging isinstructed by the instruction means.
 12. The imaging apparatus accordingto claim 1, wherein the first detection means sequentially detects apredetermined photographic subject from the image data periodicallyimaged by the first imaging control means, and the comparison meanscompares, with a result of the photographic subject detection by thesecond detection means, any one of (i) a detection result detected apredetermined number of times before a detection result by the firstdetection means when imaging is instructed by the instruction means,(ii) a detection result detected a predetermined amount of time beforeimaging is instructed by the imaging instruction means, and (iii) ahighest priority photographic subject detection result among detectionresults detected by the first detection means.
 13. The imaging apparatusaccording to claim 12, wherein the priority of a photographic subjectdetection result is determined based on at least one of proximity ofeach detected photographic subject to a center of a field angle, a sizeof each detected photographic subject in the image data, and a number ofdetected photographic subjects in the image data.
 14. The imagingapparatus according to claim 1, wherein the second detection meansdetects a predetermined photographic subject from an area in thestill-image data imaged by the second imaging control means which is thesame area as an area of a photographic subject in a detection result bythe first detection means.
 15. A non-transitory computer-readablestorage medium having a program stored thereon that is executable by acomputer included in an imaging apparatus to cause the computer toperform a process comprising: a first imaging control processing forperforming periodic imaging; a first detection processing for detectinga predetermined photographic subject from image data imaged by the firstimaging control processing; an instruction processing for instructingimaging of a still-image during the periodic imaging by the firstimaging control processing; a second imaging control processing forimaging a still-image when instructed by the instruction processing; asecond detection processing for detecting a predetermined photographicsubject from still-image data imaged by the second imaging controlprocessing; a comparison processing for comparing a result of thephotographic subject detection by the first detection processing with aresult of the photographic subject detection by the second detectionprocessing; and an informing processing for informing of a comparisonresult by the comparison processing.